1. Field of the Invention
The present invention relates to a recovering system, and more particularly to an electric power recovering system.
2. Description of the Prior Art
A typical electric circuit for an electric power device is disclosed in FIG. 8 and comprise a battery 90 having a voltage V, a coil 91 having an inductance L and having a voltage V.sub.L, a resistor 92 or an electric appliance having a resistance R, and a switch 94 for coupling the resistor 92 to the battery 90 and for energizing the resistor 92. The voltage V equals to V=IR+L(di/dt). The power equals to P=IV=I.sup.2 R+LI(di/dt); in which I.sup.2 R equals to the heat that will be generated by the resistor 92, and LI(di/dt) equals to the energy in the coil 91. If U represents the energy stored in the coil 91, then (dU/di)=LI(di/dt). U=(1/2)LI.sup.2 which equals to the area of the shaded portion as shown in FIG. 7. As shown in FIG. 7, when the switch 94 is closed in order to energize the resistor 92, the voltage of the coil 91 V.sub.L drops quickly and initially and then smoothly after time T.sub.1. The current of the coil 91 I.sub.L increases quickly and initially and then smoothly after time T.sub.1. Accordingly, as shown in FIG. 7, only in time T.sub.1 or only in the shaded area, the conversion of the energy stored in the coil 91 to power output may be excellently conducted. After T.sub.1, di/dt almost equals to zero, such that the voltage V is almost applied to the equation I.sup.2 R which means that the resistor 92 may generate a great heat after T.sub.1. This means that almost all of the electric power is wasted for generating unwanted heat. The heat may also damage the electric power device.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional electric power devices.